Air cooled air compressor



Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec.

5 Sheets-Sheet 1 Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec. 21, 1951 5 Sheets-Sheet 2 86 Mm V AIlornry Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec. 21, 1951 5 Sheets-Sheet 3 Inn mm-AMTHUI CiE/ITJN A. C. EATON AIR COOL-ED AIR COMPRESSOR Dec. 22, 1953 5Sheets-Sheet 4 Filed Dec. 21, 1951 n 1 IV. 5 g

152 Jiqi s Jfe AFTHURC. EATON- Dec. 22, 1953 A. c. EATON AIR COOLED AIRCOMPRESSOR 5 Sheets-Sheet 5 Filed Dec. 21, 1951 Nmw ARTHUR c, E4TON [ivHz- Half.

' e e win are 1 Figure 4 being; on i Patented Dec. 22, 1953 iJNiTEDSTATES FATENT OFFICE 14 Claims.

This invention relates to a novel form of air cooled air compressor ofthe rotary type including. an encased revolving rotor by means of whichair is compressed for supplying a storage tank with compressed air orfor supplying air to other devices operated by compressed air andwherein the air is initially utilized by the compressor due to therotary movement of the rotor for cooling said rotor and the partscarried thereby.

Another object of the invention is to provide an air compressor having arevolving rotor functioning similarly to a flywheel and having camactuated compressing means carried thereby and actuated by the rotationthereof for compressing air as the rotor is revolved.

Another object of the invention is to provide an air compressor whereinthe air is supplied under pressure to the compressing means eliminatingthe necessity of drawing the air by vacuum thereto thus increasing thecapacity of the compressing means, due to the fact that the air is underpressure at the commencement of the compression stroke.

A further object of the invention is to provide a novel cam means foractuating the air compressing means and which is adjustableautomatically in response to the air pressure within a tank or containersupplied by the compressor to cause the cam means to assume aninoperative position to prevent operation of the compressing means whenthe pressure in the storage tank reaches or exceeds a maximum capacity.

A further object of the invention is to provide a compressor havingnovel means responsive to an excess pressure of air in a storage tankautomatically rendering the compressor inoperative until the airpressure in the storage tank is diminished.

Still a further object of the invention is to provide an air compressorhaving a novel lubricating means to maintain its supply of lubricantunder pressure to the moving parts thereof at all times while thecompressor is in operation.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawings, illustrating presently preferred embodiments thereof, andwherein:

igure 1 is a longitudinal central sectional view, partly in sideelevation illustrating one preferred embodiment of the invention;

Figures 2, 3 and 4- are cross sectional views thereof takensubstantially along planes as in- 2 3- 3 and i -:4 of Figure Figure 5 isan enlarged fragmentary longitudinal sectional view of a portion of thecompressor;

Figure 6 is an enlarged end elevational view of a portion of thecompressor;

Figure 7 is an enlarged fragmentary longitudinal sectional view partlyin elevation of one of the compressor pistons;

Figure 8 is an end elevational view thereof looking from left to rightof Figure 7;

Figures 9 and 10 are cross sectional views of the piston rod and piston,respectively, taken substantially along planes as indicated by the lines9--;) and !0Hl, respectively, of Figure 7;

Figure 11 is a view similar to Figure 4 looking toward the inner side ofthe cam end of the compressor casing showing one modified form of camstructure;

Figure 12 is a vertical sectional view taken substantially along a planeas indicated by the line l2--l2 of Figure 11;

Figure 13 is an enlarged fragmentary plan view of a portion of one ofthe cam elements;

Figure 14 is an end elevational view thereof as viewed along the line iil4 of Figure 13;

Figure 15 is a view similar to Figure 11 illustrating another modifiedform of variable cam;

Figure 16 is a cross sectional view thereof taken substantially along aplane as indicated by the line [6-16 of Figure 15;

Figure 17 is a view similar to Figure 15 illustrating still another formof variable cam;

Figure 18 is a sectional view thereof taken substantially along a planeas indicated by the line lB-Ifi of Figure 17;

Figure 19 is a view in the same plane as Figure 18 but showing the camin an elevated, operative position as distinguished from its inoperativeposition as illustrated in Figure 18;

Figure 20 is a top plan view of one element of the cam of Figures 17, 18and 19;

Figure 21 is an edge elevational view thereof, and

Figure 22 is a fragmentary side elevational view showing one form of apressure actuated switch for use with the cam structure of Figures 1 to10.

Referring more specifically to the drawings, first with reference toFigures 1 to 10, the novel compressor in its entirety is designatedgenerally 25 and includes a casing or housing, designated generally 25which is composed of a side wall 2'5, which is preferably cylindrical,and end walls 28 and 29v pending foot members; 30 on whichihe-housingand hich ay The side wall 21 is provided with def secured to asupporting surface, not shown, for maintaining the 2s stationary.

A stationary shaft 3! extends inwardly through the central portion ofthe end wall 28 and terminates intermediate of the ends of the casing 26and is disposed axially thereof. Said stationary shaft 2| being providedwith a head 32 at its outer end to secure it to the outer side of theend wall 23 by a suitable fastening 33. A rotor, designated generally 36is journalled on the stationary shaft ill and is disposed for rotationin the casing 23, the bore 35 of said rotor which turnably engages theshaft 3| being provided with enlarged ends 36 and 13! to accom! mcdatetapered antifriction bearings v38 and 19,

respectively, which are disposed therein and in engagement with theshaft .31. The bearing 59 which is located adjacent the head or end 28abuts against an adjustable collar 413 secured to the shaft 3! toprevent the rotor 34 from sliding toward said end 28.

A driven rotary shaft l! extends axially into the casing 25 through theend wall 29 .and is journalled therein by a tapered antifriction'bearingunit 42 which seats in an inwardly opening recess 63 of the Wall 29. Thewall 29 on its outer side is provided with a stuffing box 44 surroundinga portion of the shaft ll. The shaft ii is provided with an enlargement45 which bears against the bearing 62 to prevent the shaft 3:)

from being displaced outwardly through the wall 29. The inner flangedend 56 of the shaft 41 is secured by fastenings ill to one end of acoupler as, the opposite end of which is secured by fastenings 59 to theend of the rotor 35 in which the anti-friction bearing unit 33 ismounted, so that the collar so and enlargement l5 combine to preventsliding movement of the rotor 34 in either direction on the stationaryshaft 3i and the bearing units 39 and 42 form thrust bearings which areengaged by the collar 49 and enlargement 45, respectively.

The rotor 34 has an annular outwardly extending flange 513 locatedadjacent the end of its central or hub portion 5! in whichthe recess 37is formed and which flange 5B is provided adjacent its periphery with anannular flange 52 which projects at a right angle to the plane of theflange 5c and toward the end wall '29.

The flange or wall 58]. and the annular peripheral b flange 5-2 of therotor 3 4 combine to form an annular chamber 53 surrounded by theperipheral flange 52; and which is disposed between said flange and theoppositelend of the hub 5|, which is secured to the coupling 48. Saidannular chamber 53 opens toward the end wall 29. The peripheral flange52 is provided with two diametrically opposed internal enlargements 5don its inner side which are disposed within the chamber 53, formingcylinders 55 which open toward the end wall 29. The outer surface of theperipheral flange 52 and the contiguous peripheral edge of the wall 50are provided with spaced annular ribs or enlargements 56 and 5'! tivelywide radially fits on the peripheral edge b e l 5t with portion .01 ones de thereof wh is located adjacent its inner .edge abutting aaeainstthadjacent side of th annul r .rib 56 and to which the ring 58 is securedby circumferentially spaced fastenings 59. If desired, the

ring 58 may be formedintegral with the wall v as extending therearound.A ring 58 which is rela- .50 ;c. outer outer side of the ring 58 areeach preferably provided with cooling fins 60.

A plurality of corresponding vanes 61 are mounted on the shoulders 56and 51 in circumferentially spaced relationship to one another, each ofsaid vanes 6| being curved in the same direction from its inner to itsouter edge and having an arcuately bowed flange projecting from theconvex side of its inner edge and which is likewise arcuately bowedtransversely. Said flanges 62 have their end portions resting on theshoulders 55 and 51 and the flange 52 of each vane 6| extends toadjacent the concave side vof the next trailing vane 6i to provide arestricted slot 53 therebetween. Each of the flanges 52 is connected toeach of the shoulders 56 and '51 by at least one fastening St. Theflanges combine with the shoulders 56 and 57 and with the portion of theexterior surface of the annular peripheral flange 52, located betweensaid shoulders, to form an annular chamber having the outwardly openingslots 63 and which is provided with two inwardly extending passages 165which extend inwardly from said annular chamber 66 and one of whichopens into an annular internal enlargement 67 of each of the cylinders55. A second relatively wide ring 68 is disposed on the outer end of theouter surface of the peripheral flange 52 and against the outer side ofthe other shoulder 5'! and said rings '58 and 68 extend outwardly to theouter edges of the vanes BI and to adjacent the inner surface of thecylindrical wall 21 and combine with said vanes to form air scoops fordeflecting air inwardly through the slots 63 into the annular chamber55, when the rotor 34 is revolved in a direction so that the outer edges:of the vanes Si constitute their leading edges, or counterclockwise asseen in Figure 2. It will likewise be readily apparent that the vanes 6!may be secured in reversed positions to function :in the same mannerwhen the rotor is revolved in the opposite direction or clockwise asseen in Figure 2.

As illustrated in Figures '1, 2 and 4, the cylindrical wall 2! isprovided with spaced annular external ribs 69 on which is disposed anannular band or strip lo which is secured by fastenings ll adjacent theside edges to the peripheries of the ribs 69 to combine therewith andwith the portion of the cylindrical wall 21 which said band surrounds toform an annular outer air chamber 12. Said wall portion is provided witha plurality of circumferentially spaced longitudinally extending slots13 which communicate with the chamber 72 and which open into theinterior of the casing 25 between the rings 58 and 68. The band 70 ispreferably provided with two air inlet conduits M which open downwardlyinto the chamber 12, as best illustrated in "Figure 2, each of which ispreferably provided at its upper inlet end with an air filter 15 for fltering the air entering the casing 26.

The stationary shaft 3! is provided with an annular groove lfi in itsperiphery which is connected by radial passages l? to one end of alongitudinal passage 18 of the shaft 3!, and the opposite end of whichopens outwardly through the head 32 and is in communication with aconduit 553 which is tapped into said end of the passage 18. The conduit19 is adapted to communicate at its opposite end with any suitable airstorage tank 80, such as illustrated in Figure 22 or with any othersuitable device adapted to be lie tn'oroperatedcylinders 55 are providedwith restricted seats 85 at their inner ends which open into cavities 82formed in the rotor wall 50, each of which cavities has a bore 83extending radially inward therefrom into the hub bore and whichcommunicates with the groove 76. A valve housing 8 5 has an enlargedflanged end 85 seating in each seat 8! and projects therefrom into theadjacent cavity 82. Each housing 84, as best seen in Figure 5, has abore 81'; extending longitudinally therethrough provided with anenlarged externally threaded outer end 57! which opens into the cavity82 and a restricted inner end 83, defining a valve seat which opens intothe cylinder 55. A perforated valve stem guide and spring seat 89 isthreaded into the bore end 3? to slidably guide the stem iii) of a valve9! which seats in the valve seat 88 and against which bears an end of aspring $2 mounted on the stem 9!] and having its opposite end abuttingthe seat guide 89.

Each cylinder 55 has a liner or sleeve 93 disposed therein which abuts aportion of the housing head $5 in the same cylinder for retaining saidhead against the seat 3!. Each sleeve $3 is provided with a series ofcircumferentially spaced openings M which open into the groove 6?. Apiston 95 is reciprocally mounted in each sleeve 93 and has a piston rod96 extending therefrom reciprocally through a guide 97 which is providedwith a flanged head @8 which closes the open end of its associatedcylinder 55 and which is secured by fastenings 92 to the end of theenlargement forming said cylinder. The heads 98 likewise retain thesleeves $3 in seated positions and tightly against the housing head 35.

As seen in Figure 1, an annular internal wall ill!) is secured inliquid. tight engagement around a part of the inner surface of thecylindrical wall 27 between the rotor 3- and end wall as. The inner edgeof the wall ice is spaced a sub stantial distance from the longitudinalcenter of the casing 26. The guides S! are provided with grooves it}!which fit the inner edge of the wall N30. The bottom portions of thewalls 23 and we combine to form a sump or storage chamber for oil, asseen at E2 in Figure 1. It will also be noted that portions of the guideheads $38 overlie the outer surface of the peripheral flange 52 and abutagainst the outer side of the ring memher 56 to retain said ring memberon the flange E2 and against the outer side of the rib 5?.

Each piston rod is provided with a wheel fork its its opposite end inwhich is journalled wheel or roller Hi l which is disposed to ride onthe inner surface or" the wall 28 in a circular path when the rotor 3 isrevolved and said wall 29 is provided on its inner side in the path oftravel of the rollers i535 with two arcuately or circumferentiallyextending cam groove H35 the beds of which are inclined upwardly andtoward the inner surface of the wall it in a counterclockwise directionfrom end-to-end thereof so that as the rollers EM travel about the innersurface of the wall 25, each roller in moving counterclockwise willsimultaneously be displaced by a spring l .35 into the deep end of a camgroove Hi5 and in traveling counterclockwise will roll up the inclinedbed of said groove back onto the surface of the wall 28, each rollertell engaging each cam groove 1% during each revolution thereof to causeeach of the pistons 95 to make two complete strokes in each revolutionof the rotor 3 The springs MG are mounted on the piston rods between theouter ends of the guides 9"? and the forks H33.

Each piston rod 95, as best seen in Figure 7, is threaded into one endof a bore I01 which extends through the piston ilE and said piston rodcarries a lock nut I88 which is threaded thereon and abuts against theouter end of the piston. The opposite end of the bore It? is providedwith a valve seat its for an outwardly opening valve iii which seatsthereagainst and has a valve stem l i extending inwardly of the boreill! from the valve il through a perforated guide H2 in which said stemis reciprocally mounted for guiding the movement of the valve H2. Theguide l 12 is threadedly mounted in the bore Hi? between the valve seati as and the adjacent end of the piston rod An expansion spring I !3 carried by the valve stem Ill normally retains the valve H8 in a seatedposition. The piston is provided with a plurality of air passages EMwhich open into the intermediate portion of the bore ill! and outwardlyof the rear face of the piston 95. The periphery of the piston 3-5 isprovided with spaced piston rings E E5.

A gear H6 is disposed around the end of the hub 55 located adjacent thecoupling 43, and is preferably formed integral therewith and meshes witha pinion ill fixed to a shaft H8 which drives a pump 5 is. The pump H9is disposed between the rotor 3t and end wall 2e, adjacent the of thecasing 25 and is supported by a bracket lii secured to the inner side ofthe end wall An inlet conduit l2! has an inlet end opening into the sumpor oil reservoir I82 through the cylindrical wall 2. and has an oppositeend tapped into the inlet side of the pump H9, said conduit lZl having aportion disposed externally of the casing 255, as illustrated in Figure1, including a bore l22 extending through the wall 29. An outlet conduit12% has one end tapped into the outlet side of the pump H9 and has itsopposite end tapped into the stationary shaft head and communicatingwith a passage li 'l which extends longitudinally of said head and ofthe shaft 35. The conduit I23 extends along the underside of the casing26 and along portions of the ends thereof, as seen in Figure l, andincludes a bore portion 525 extending through the end wall 29, adpacentthe bearing 32 and has a branch port iZE opening into and lubricatingthe bearing 22. The annular groove it of the shaft Si is located betweentwo annular grooves till, formed in a periphery of said shaft 3!, eachof which contains a plurality of split rings i223, the split portions ofwhich are disposed out of registry to provide a substantially solidannular band or ring, The lubricating passage 52d has branch ports I29for lubricating the rin s of each groove 12'! and branch port 539 forlubricating the other thrust bearing 89. The other end of the passage {2t opens into an annular uoove iii! in the periphery of the shaft 3iwhich is located adjacent the bearing 38 and which groove communicateswith radial ports 132 of the hub 5i, to each of which is connected anend of a lubricating conduit 533. The opposite ends of the oonduitslttare tapped. into the outer ends of radial passages 53-4, as best seen inFigures 1 and 5, the inner ends of which passages lubricate the bores ofthe guides ill, in which said passages are formed for lubricating thepiston rods ea. As seen in Figure '7, each piston rod 95 has alongitudinally extending lubricating passage #35 including a radialbranch passage its by means of which the :lubricant 'IOZis supplied tothe "passage I35 from the passage I34 of the guide 97 in which saidpiston rodQB is reciprocally disposed. One end :foregoing it will bereadily apparent that when the rotor which with the vanes or scoops 6|forms a turbine wheel, is revolved, the pum H9 will be actuated forpumping oil I02 from the reservoir as seen in Figure 1 through the pipesor conduits I2! and I23, through the passage I24 and conduits I33 forlubricating the rotor bearing and other parts of the rotor which engagethe stationary shaft SI and for also lubricating the pistons 95, pistonrods 96 and the wheels or rollers I53.

Assuming that the drive shaft M is being revolved as by means of anelectric motor, not shown, it will be readily apparent that the rotorturbine wheel 34 will be rotated at the same speed as said drive shaftby being connected thereto by the coupling is and will turn on thestationary shaft 3i. As said turbine wheel is revolved, the vanes orscoops 6i turning counterclockwise'as seen in Figure 2 will create asuction in the outer annular chamber 12 to cause air to be drawn intosaid chamber through the air-intakes It provided with the filters 15.The air will be drawn from said annular chamber 12 by the scoops 6|inwardly through the ports 73 into the turbine wheel pockets formed bythe vanes or scoops BI and the rings 58 and 63. The air impingingagainst the forward, concave sides of the scoops will be deflectedinwardly through the restricted slots 63 into the inner annular airchamber 56 in which chamber the air will be compressed and forced underpressure radially inwardly through the passages 55 into the annulargrooves 67 of the two cylinders 54 from which the air will escape underpressure through the sleeve openings 9 into the interior of the sleeves93.

Asthe turbine wheel 34 is revolving to thus charge the cylinder sleeves93 with compressed air, the wheels or rollers 54 will be riding theinner surface of the end wall 29, as best seen in Figure 3, in acounterclockwise direction and as each roller 9e reaches each of the camgrooves I05 it will be projected by its spring I58 into the bed of saidgroove at its deepest end, thereby allowing the two springs I9 5 tosimultaneously move the pistons 95 to their retracted positions of:Figure 1 adjacent the guides 9i and so that the openings 9-: will beexposed to the left of the pistons 95 for fully charging the cylindersleeves 93 between the pistons 85 and the cylinder heads 85. As theturbine wheel continues to turn counterclockwise, the rollers its willride up the inclined bottoms of the cam grooves I05 and during theirinitial travel therealong, the pistons '95 will be displaced to the leftfor initially closing the ports or openings 94 and for thereafterfurther compressing the air between the pistons and cylinder heads 85.This will cause the valves 9| to be opened to allow the air to escapethrough the bores 83 and guides 89 into the cavities 82, through theradial pas- 8 sages into the annular groove 15 of the shaft 3| thencethrough the passages 11 into the passage I8. The compressed air willpass through the passage I8 and conduit I5 into the storage tank 86, asseen in Figure 22. As each piston moves to the left past the openings94, additional air will be forced into the sleeves 93 behind or to theright of the pistons 95, as previously described, to fill said sleeveswith compressed air to the right of the projected pistons 95. When therollers I56 have completed a half revolution and each drops into theother cam groove I05, the pistons 95 will again be retracted by thesprings I06 and return to their positions of Figure 1 and in so movingfrom left to right, the compressed air to the right of the pistons willflow from right to left through the passages Hi and bores I61, andthrough the guides M2 to unseat the valves III] to allow the compressedair to escape to the opposite or left hand side of each piston. Thecylinder sleeves will thus be initially charged with air duringsubstantially the entire return stroke of each piston and will befurther charged with compressed air as the pistons pass to positions tothe right of the openings 94, as previously described. It will beunderstood that each piston 95 executes two compression strokes and tworeturn strokes for each revolution of the turbine wheel 35. If desired,it will be readily apparent that four equally spaced cylinders andpistons can be provided in lieu of the two cylinders 54 and two pistons55 and in which case either two or four cams ")5 could be provided,depending upon the amount of air required; however the two compressorcylinders with the two cams is equal to a four cylinder compressor andis capable of compressing more air than a four-cylinder compressorhaving cylinders of the same size due to the compressing of the air inthe cylinders on the backstroke of the pistons rather than having airdrawn into the pistons by suction, as is conventional and which causes avacuum to exist in the conventional cylinder as the piston thereofstarts its compression stroke,

Any suitable automatic switch means may be utilized for de-energizingthe electric motor by means of which the shaft M is driven, as forexample, the diaphragm switch MB as illustrated in Figure 22 which isconnected to the storage tank 89 so that when an air pressure exists insaid tank above a predetermined, safe pressure the air impinging on thediaphragm of the unit G9 will cause the rod Isl to swing the arm I42upwardly on its pivot I43 to thereby elevate the connecting rod I44 tothus swing the switch arm I45 upwardly to move the switch let, which isadapted to be interposed in the circuit of the electric motor, notshown, to a circuit interrupting position. The electric motor will thusbe de-energized to stop operation of the turbine wheel 34 until thepressure in the tank 35 diminishes sufficiently so that the adjustableweight I 41 will swing the lever I42 downwardly and cause the switch armI45 to be swung downwardly and back to a circuit closing position of theswitch M6 to thereby again energize the electric motor for driving theturbine wheel 34.

The shaft AI may also be driven by other means not capable of beingstarted and stopped by the switch 146,-as for example, a gasoline ordiesel engine, not shown, in which case another type of cam may beutilized to prevent the building up of too great an air pressure in thestorage tank, as for example the cam means as 9 illustrated in Figures11 to 14 comprising an annular groove Ml formed in the inner side of theend wall 29a in which are positioned a pair of corresponding oppositelydisposed cam tracks, designated generally M8, each including twoarcuately curved strips 549 having adjacent ends which are connected bya hinge 55d. Said cam strips Mid have remote ends which slidably engageportions of the bed of the groove i i? and are provided adjacent saidremote ends with crossarms ltd which extend into undercut inwardlyopening grooves 552 which are formed in the upright side walls of thegroove Ml and which open into the sides of said groove. A pin I53extends upwardly through each arm lei and is reciprocally mountedtherein and has a roller let journalled in its upper end, which rollersengage the top walls of the grooves 152 and are yieldably urged upwardlyinto engagement therewith by springs I55 which are carried by the pins:53 and urge said pins and rollers upwardly. The pin itii oi the hingeI56 has an outer end which extends into another recessed portion I? ofthe end wall 29a and on which is swingably mounted one end of a leverI53 on the opposite end of which is journalled a shaft W9. A roller I69is journalled on the outer end of the shaft I55} and engages a grooveifiI formed in the outer wall of the recess 57. A link I62 is likewiseconnected to the shaft I59 and to one end of a pull spring Hi3 which isanchored to the wall Zea at its opposite end at I64. It will be readilyapparent that the spring its will exert a pull on the lever its to causethe roller its to travel toward said spring for swinging the lever I58toward an upright position to elevate the hinged intermediate portionI50 of the cam track his so that the rollers we will pass over each ofthe cams Hi8 during each revolution of the turbine wheel St to execute apumping operation in the same manner as previously described inreference to the form of the invention as illustrated in Figures 1 to10.

A cylinder 5'65 has an open end which is fastened to the outer side ofthe wall 29a and contains a piston I65 having a piston rod it? whichextends slidably through a stuffing box E58 mounted in the end wall 29a.The opposite end of the piston rod It? is connected to the opposite endof the hinge pin I55. A spring IE9 carried by said piston rod urges thepiston rod inwardly of the wall 290. The storage tank tile is providedwith a blowoff valve lit which opens into a housing I'll which isconnected to the inner portion of the cylinder m5 by a conduit Hi2 andwhich is additionally provided with a vent port H3. When the airpressure becomes excessive in the tank 86a it will overcome the pressureof the spring Ilila to open the relief valve i'iii allowing the air toescape through the conduit P22 into the cylinder IE5 between thestufiing box I68 and the piston 165. The piston I66 will thus be forcedby the compressed air toward the outer end of the cylinder I55 and thepiston red It! will exert a pull on the hinge pin I56 against the actionof the springs IE3 and ltd to draw the hinged ends of the cam sectionsHi9 outwardly of the end wall 29a to position said sections MS withtheir ends more nearly in the same plane thereby reducing the angle orpitch of the track sections 549 to thus minimize the extent that thepistons t5 will be actuated by said cam to thereby reduce or totally.

eliminate the pumping operation of the pistons 55, It will be understoodthat each cam I43 is provided with all the structure previouslydescribed and that both cams are increased or decreased in pitchsimultaneously. A limited amount of air will escape from the housing IIithrough its vent aperture H3 and as the pressure in the tank adiminishes, as by utilizing a part of the air therein, the air willescape from the cylinder I35 through the vent lit and the spring itscooperates with the spring I53 to urge the track sections it back towardthe maximum pitch position for increasing the length or" the strokes ofthe two pump pistons t5 and accordingly the amount of air which will bepumped thereby.

Figures 15 and i6 illustrate another form of variable cam and whereinthe end wall 292) is made relatively thin and is provided with twodiametrically spaced supports i'i l which proiect from its inner sideand which support the ends of two cam tracks, each designated generallyI75 and each of which is substantially semicircular. Each cam track H5is formed of two corresponding sections lit the adjacent ends of whichare connected by hinges ill, a pin lit of which extends outwardly of theouter edges of the sections W5 and is secured to one end of a lever I79.A connecting rod or lint: use is pivotally connected at N35 to theopposite end or the lever Ill; and has a free end fastened to one end ofa, pull spring I82 which is anchored at its opposite end by a pin use tothe wall 2st and which urges the lever [is to swing in a clockwisedirection, as seen in Figure 16 with its lastznentioned end sliding andiulcruming on the wall 2253b for urging the hinged ends of the sectionsI16 inwardly and while the opposite, free ends slide on the supportsIlhi for causing the cam track sections lit to assume elevated operativepositions, as illustrated in dotted lines in Figure 16.

A cylinder Iliiib containing a piston I661) and a connecting rod Hill)is supported on the outer side of the wall 2% in the same manner as thecylinder Hi5, previously described, and said piston rod extends inwardlythrough the wall 2% and is pivotally connected to a downwardly oil'- setintermediate portion il'tb of the hinge pin lit. The piston rod It???carries a spring web that also urges the piston rod and piston inwardlyof the wall 2% for urging the cam track sections lit to their dottedline positions of Fig ure 16. Air under pressure is supplied to thecylinder i651: inwardly of the piston Itth by a conduit H22) which isconnected to a storage tank, not shown, corresponding to the storagetank 86a. by a blowofi valve unit, not shown, corresponding to the unitas illustrated in Figure 12, so that the pistons with of the twocylinders its?) will move the sections or" the two cam tracks H5 intocoplanar full line positions as illustrated in Figure 16 when anexcessive air pressure exists in the tank to which the conduits iizibare connected, so that the rollers engaging said cam tracks will not bedisplaced away from the end wall 2%, in order that the pistons will notreciprocate when the storage tank is fully charged with compressed air.

Figures 17 to 21 illustrate another form of variable cam tracksincluding an end wall 290 having parallel cam track receiving recessesits the side walls of which are provided with inwardly opening grooves585 for receiving plates itt, the side edegs of which are slidablymounted in said grooves for movement toward and away from one anotherand are urged toward one anasses l 1 other by expansion springs I81. Acylinder I650, piston I660 and piston rod IE'I'c form a unitcorresponding to the piston, cylinder and piston rod units of Figures 12and 16 and wherein the piston rod is urged inwardly of the wall 280 by aspring I590, it being understood that one of said units is associatedwith each groove it. However, the inner end of the piston rod I670 bearsagainst the intermediate portion of a rigid inverted V-shaped cam trackI88, the apex of which is normally disposed beneath and between theadjacent ends of the plates I85, when the cams are in inoperativepositions, as illustrated in Figure 18. A lever, link and spring unitIlec, H380 and I820, respectively, similar to the unit of Figures 15 and16 is connected to a rod or shaft I180 which projects laterally from theupper end of each piston rod Idle and said lever, link and spring unitsare disposed in separate recesses its of the wall 290 which open intothe outer sides of the recesses list and each of which has an outer wallcontaining a guide groove ItEi for an extension of an end of the pin Iticonnecting each lever I190 and link I390, so that said unit can be urgedwith the piston and piston rod inwardly, in combination with the springI690 for urging the cam track It?) to a projected, operative position asillustrated in Figure 19. The plates I86 are provided with rollers leion their inner sides, near their adjacent ends by means of which saidplates are spread away from one another against the action of thesprings is; when the cam tracks I88 are moved to projected positions asillustrated in Figure 19 by the springs IfiQc and 582e, so that therollers ltd at each revolution of the turbine wheel 34' will ride overeach of the two sets of plates I85 and over the inclined surfaces ofeach of the cam tracks I38 to cause each or the pistons 95 to completetwo strokes at each revolution of the turbine wheel 34. The cam tracksI83 are moved to retracted positions by air entering the cylindersIfitic" inwardly of the pistons I660 through conduits H20, all in thesame manner as previously described and as full illustrated in Figure12, so that'when a storage tank, not shown, is fully charged withcompressed air the cam tracks M8 will be in retracted positions asillustrated in Figure 18'to cause the rollers I3 2 to ride over theplates I85 and the inner surface of the wall 290 without being displacedlongitudinally of the turbine casing suficiently to pump air from thecylinders 55 through the cylinder heads 34.

In order to insure that the rollers I04 will be disposed for rollingengagement at all times either with an inclined cam surface or a flatsurface, each fork m3 is secured nonrotatably to its piston rod 95 by asetscrew I92 Additionally, the piston rods 96 are provided with flatportions I93 so that the piston rods are of noncircular cross section,as best seen in Figure 9, for slidably and nonrotatably engaging boresI94 in the guide heads 9'! which are of noncircular cross section, asbest illustrated in Figure 6. Each fiat surface I93 extends to the outerend of its piston rod 96 so that the piston rods may be inserted throughthe bores I94 before the forks "33 are secured thereto. By thisconstruction, the oil passages I36 will always be properly positioned tomove into registry with the oil passages I34.

Various other modifications and changes are contemplated and mayobviously be resorted to, without departing from the spirit or scope ofthe invention as hereinafter defined by the appended claims;

, 12'- I claim as my invention: 7 1'. A rotary type air compressorcomprising a casing having first and second end walls and a cylindricalside wall, a stationary shaft secured to one of said end walls andextending axially into and partially through the casing, a drivenrotaryshaft extending axially into the casing through the other second endwall and journalled therein, a rotor journalled on the stationary shaftfor rotation within the casing and coupled to said driven shaft androtated thereby, a turbine unit secured around the periphery of therotor for rotation therewith within the casing and extending outwardlytherefrom to adjacent the cylindrical wall of the casing and including aplurality of circumferentially spaced vanes. forming scoops havingleading outer edges disposed in advance of their trailing inner edges,said cylindrical casing wall having air inlet ports adjacent saidturbine unit through which air is drawn into the casing from pockets ofthe turbine unit formed between the vanes thereof by rotation of therotor, cylinders formed in said rotor and disposed longitudinallythereof between the turbine unit and the stationary shaft, said rotorbeing provided with air passages leading from the pockets of the turbineunit to said cylinders, said rotor and stationary shaft havingcommunicating passages extending from corresponding ends of saidcylinders and opening outwardly of an outer end of the stationary shaft,pistons reciprocally mounted in said cylinders having piston rodsextending therefrom away from the last mentioned rotor passages andtoward the second casing end wall, spring means carried by said pistonrods for urging the piston rods and pistons toward said second end wall,and cam means associated with the second end wall engaging said pistonrods for intermittently displacing the piston rods and pistons towardthe last mentioned rotor air passages for compressing air in thecylinders and forcing the compressed air through the last mentionedrotor passages into the stationary shaft passage, said turbine forcingair under pressure into said cylinders in certain positions of thepistons relatively to the cylinders whereby the pistons on theircompression strokes will initially operate on air partially compressedinsaid cylinders.

2. A rotary type compressor as in claim 1, said rotor and turbine unitbeing cooled by the air drawn into the casing by the turbine unit andexpelled inwardly therefrom into said cylinders, said rotor having anannular air chamber surrounding a portion of its periphery communicatingwith the first mentioned rotor passages and opening into the turbineunit pockets in which the air is compressed and propelledcircumferentially of the rotor to the first mentioned rotor passages forcooling the peripheral portion of the rotor.

3. A rotary type air compressor as in claim 1, said first mentionedpassages opening into the cylinders remote from said cylinder ends andbeing closed by the pistons during the initial movements thereof fromretracted positions, remote to the cylinder ends, toward said cylinderen s.

4. A rotary type air compressor as in claim 3, each of said firstmentioned passages including an annular inner portion formed in thecylinder bore, each of said cylinders including a sleeve in which thepiston is reciprocally mounted havinga plurality of circumferentiallyspaced ports extending radially therethrough and communicating with theannular portion of the first sure into the cylinders between the pistonsand i guide members will pass through the pistons toward the cylinderheads during the movement of the pistons toward the guide members forcharging the cylinders with compressed air on the I return strokes ofthe pistons.

6. A rotary type air compressor as in claim 5, and lubricating means forlubricating the rotor, pistons and piston rods including a rotary pumpmounted in a stationary position within the casing and driven by therotor, a lubricant reservoir formed in a portion of the casing andconnected to the pump intake, and a conduit leading from the pump outlethaving branch passages for lubricating the driven shaft, rotor, pistonsand piston rods.

7. A rotary type compressor as in claim 6, said outlet conduit of thepump including a passage extending longitudinally of the stationaryshaft and an annular groove formed in a portion of the periphery of thestationary shaft.

8. A rotary type air compressor as in claim 1, the periphery of saidrotor being provided with longitudinally spaced annular ribs on whichsaid turbine vanes are mounted and secured, said turbine unit includingring members mounted on the periphery of the rotor against the remotesides of said annular ribs and extending outwardly therefrom to theouter, leading edges of the vanes.

9. A rotary type compressor as in claim 8, said turbine vanes eachhaving a flange at its inner edge extending circumferentially therefromto adjacent the inner edge of the next trailing vane and combiningtherewith to form a narrow passage between pockets formed by theadjacent turbine vanes and turbine rings and the annular air 1 chamberformed between the rotor periphery, the vane flanges and said rotorribs.

10. A rotary type air compressor as in claim 1, said second end wallhaving at least one arcuately extending recess on its inner faceprovided with a bed portion inclined from end-to-end thereof forming acam groove constituting a part of said cam means, and rollers journalledon the ends of the piston rods located remote to the pistons forengaging the cam groove bed on the inner face of i i 4 piston rodrollers when the cam tracks are in projected, operative positions fordisplacing each of the pistons toward the last mentioned rotor airpassages on each revolution of the rotor, and means responsive to anexcess pressure of air in a storage container supplied by the aircompressor for displacing said cam tracks away from the rotor to aninoperative position whereby the piston rods are not displaced towardthe rotor when the storage container is fully charged to render the aircompressor inoperative.

12. A rotary type air compressor as in claim 11, each of said cam tracksincluding a pair of arcuate sections having adjacently disposed hingedends which are displaceable toward and away from the rotor.

13. A rotary type air compressor as in claim 11, each of said cam tracksincluding a pair of reciprocally mounted plates disposed for slidingmovement toward and away from one another and spring urged toward oneanother, and an inverted V-shaped track element spring urged toward therotor between the adjacent ends of said plates and forming the camportion of the track for displacing the plates away from one another,said cam track portions being displaced away from the rotor to aninoperative position by an excess air pressure in the storage container.

14. A rotary type air compressor comprising a driven rotor, a turbineunit mounted on the periphery thereof including circumferentially spacedvanes having outer leading edges forming scoops adapted to draw air intoturbine pockets formed between the adjacent vanes and for propelling theair inwardly toward the axis of the rotor, said rotor having an annularair chamber disposed inwardly of the turbine pockets into which the airis forced from the turbine unit and compressed, said rotor beingprovided with at least one cylinder disposed between the axis thereofand said annular air chamber having a passage communicating with saidair chamber through which air is forced under pressure for charging saidcylinder with compressed air, a piston reciprocally mounted in saidcylinder and spring urged toward one end thereof, cam meansintermittently displacing the piston toward the opposite end of saidcylinder, and an air conduit adapted to contain air under pressureincluding a passage formed in the rotor and communicating with the lastmentioned end of said cylinder through which air is forced underpressure when the piston is displaced by said cam means toward the lastmentioned cylinder end.

ARTHUR C. EATON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,453,266 Rockwell Nov. 9, 1948 2,540,328 Gray Feb. 6, 19512,552,518 Churchman May 15, 1951

